The present invention relates to filtering apparatus for purifying a few gallons of drinking and cooking water.
At present consumers may purchase plastic 2-3 gallon plastic containers of purified water at supermarkets. Some of these containers have a small valve on one side, thus the containers may be placed in a home refrigerator, and the water dispensed cold directly into a drinking glass. However, conveying these filled, and therefore heavy and bulky, containers home is awkward, and there is no convenient facility available for refilling the container with freshly filtered water and thus minimizing the high retail cost and the waste of throw-away plastic containers.
There have been a number of inventions teaching apparatus whidch use gravity to carry water from one container through a filter to another. In order to provide background information so that this invention may be completely understood and appreciated in its proper context, reference is made to a number of prior art patents as follows:
The Sherwood U.S. Pat. No. 537,489 shows two boxes connected by a hinge. The upper box is not actually a container as its bottom is actually a filter through which water can flow. The apparatus may be filled from above and the water flows through by gravity. The upper box is positioned directly over the lower container-box which has a valve on the side. Since the lower container is hinged to the upper box, space would be wasted if the apparatus were placed in the refrigerator.
The White U.S. Pat. No. 2,502,298 shows two identical containers each with a single opening. By use of a complex structure to support the inverted upper container, the water flows by gravity through a separate filter to fill the lower container. The fact that there is only a single opening to the containers makes it necessary to have a complex supporting structure so that the upper container can be inverted directly over the lower container. It is apparent that this patent is directed toward the containers used in office water fountains which might be expected to be refilled at a central location where such a complex and rugged structure could be justified financially.
The Ward U.S. Pat. No. 3,536,197 has means for connecting the filter in vertical alignment to the upper container. There is a one-way ball valve in the bottom of the upper container to allow air to enter the container after it is turned over so that the water can flow out, and yet not to let the water flow out while the container is being filled while upright. This valve can not be used to allow water to flow through it to dispense water from the container. There is no valve attached to the lower container, so it cannot be used as a dispenser.
The Behrman U.S. Pat. No. 4,094,779 is similar to that of White, above, except that there are valves controlling the single opening for each of the two containers in order to make it simple to invert the upper container without spilling, and to slow the rate of flow should the water not be in contact with the filtering medium long enough at a higher rate of flow. Behrman specifically mentions the requirement fo inverting the upper container.
The Sway U.S. Pat. No. 4,419,235 has means for connecting the filter in vertical alignment to the upper container. There is no valve attached to the lower container so that it cannot be used as a dispenser.
The White, Behrman, and Sway references teach that the containers are symmetrical about a vertical axis. Thus to filter the outflow from one container into the other, the containers are deployed one directly above the other. This typically requires complex, yet strong structures. The Sherwood reference, while not depicting a perfectly symmetrical system, in that the lower container has a valve on the side, nonetheless has the feature that the flow from the upper container emerges from directly underneath, thus requiring that the two containers be deployed directly one above the other and thus requiring that the supporting structure, in this case the containers themselves, be strong and stable.
Whatever the precise merits, features, and advantages of the above cited references, none of them achieves or fulfills the purposes of the present invention.